You may want to look at signing up for the Amex Aeroplan Plat card (assuming your trip is still a few months away), since for an annual fee of $399 you would be able to take advantage of the 2 for 1 cert and buy a C class ticket. This could save you money and save you a whack of points, and you could always cancel the card after the first year if the other benefits were not appealing.

I concur that the basinet may or may not work for you 10 month old, but it is worth getting the bulkhead seat just in case (and having a wall doesn't hurt either for "containment"). The advantage of 3 Y is the safety factor in the event that you hit extreme turbulance. I would be tempted to do a two for one C fare, plus a third J cabin seat on points if you can swing it. That is by far the most comfortable and safest approach.

SG